Ballasted anaerobic method for treating wastewater

Abstract

A ballasted anaerobic system for treating wastewater including at least one anaerobic treatment reactor. A weighting agent impregnation subsystem is configured to mix weighting agent with the biological flocs to form weighted biological flocs to create a weighted anaerobic sludge blanket in the at least one anaerobic treatment reactor. A weighting agent recovery subsystem is configured to recover the weighting agent from excess sludge and reintroduce the weighting agent to the weighting agent impregnation subsystem.

What is claimed is: 
     
       1. A ballasted anaerobic method for treating wastewater, the method comprising:
 receiving influent wastewater in at least one anaerobic treatment reactor; 
 forming biological flocs in the at least one anaerobic treatment reactor; and 
 impregnating weighting agent into the biological flocs to form weighted biological flocs; 
 allowing the weighted biological flocs to settle to create a weighted anaerobic sludge blanket; and 
 directing the wastewater through the weighted anaerobic sludge blanket to provide a treated effluent. 
 
     
     
       2. The method of  claim 1  further including the step of recycling the weighting agent. 
     
     
       3. The method of  claim 1  further including the step of providing weighting agent in which the majority of the weighting agent has a particle size less than about 100 μm. 
     
     
       4. The method of  claim 1  further including the step of providing weighting agent in which the majority of the weighting agent has a particle size less than about 40 μm. 
     
     
       5. The method of  claim 1  further including the step of providing weighting agent in which the majority of the weighting agent has a particle size less than about 20 μm. 
     
     
       6. The method of  claim 1  further including the step of enhancing the quality of the treated effluent by reducing suspended solids and associated contaminants therein. 
     
     
       7. The method of  claim 1 , further comprising wasting excess sludge from the at least one anaerobic treatment reactor.